BA I Geography (H)

Paper- III A ( India and Bihar: Regional Study)

Unit- 1Topic- Physiographic Division of India

India is the seventh largest country in theworld. The country is bounded by the greatHimalayas in the north and the IndianOcean in the south. It stretchessouthwards and at the Tropic of Cancer,the shape of the country tapers into a capeform near the Indian ocean. The southernpart is flanked by the Bay of Bengal on theeast and the Arabian sea to the west.

India is located entirely in the northernhemisphere. The mainland extends toabout 3214 km from north to southbetween the extreme latitudes. It alsoextends to about 2933 km from east to westbetween the extreme longitudes. It coversan area of 32,872,631 sq.km. Indiansubcontinent is characterized by a greatand diversified physiographic conditions. Ifwe look at the distribution of physiographicunits, mountains occupy 10.6 %, hillsoccupy 18.5%, plateaus occupy 27.7% andthe plains occupy 43.2%

They are classified into the following physiographic units :

1. The Himalayas and other ranges.

2. The Indo-Gangetic plain.

3. The Thar Desert

4. The Peninsular Plateau.

5. The Coastal belts

6. Islands.

The name "Himalaya" means "the abode or houseof snow" in Sanskrit (i.e. hima "snow", and ālaya"abode or house".

The Himalaya mountain range is the highestmountain range on the earth situated to the north ofIndia

These mountain ranges run in a west-east directionfrom the Indus to the Brahmaputra.

The Himalayas represent the loftiest and one of themost rugged mountain barriers in the world.

The great Himalaya is one of the young foldmountains.

The Himalayas run along the northern borderof India.The width varies from 400 km in Kashmir to150 km in Arunachal Pradesh.The Himalayas form an arc which is about2,400 km long.The altitudinal variations are greater in theeastern part than in the western part.There are three parallel ranges in itslongitudinal extent (i.e. The Great or InnerHimalayas or Himadri, The Lesser Himalaya orHimachal and The Shiwaliks).

This is the northernmost range and is also known as'Himadri'.This is the most continuous range.It contains the loftiest peaks.The average height of peaks in this range is 6,000 meters.All the prominent Himalayan peaks are in this range.The folds of the Great Himalayas are irregular in nature.The core of this part is composed of granite.Because of the lofty heights, the peaks of this range areperennially covered with snow.Famous glaciers like the Siachen Glacier, the Gangotri andYamunotri, etc.

•This range lies towards the south of the Great Himalayas.

•The altitude of peaks in this range varies from 3,700 to 4,500meter.

• The average width of this range is 50 km.

•This range is mainly composed of highly compressed andaltered rocks.

•The most important mountain range here is the Pir Panjalmountain range and it is the longest range.

•Dhaula Dhar and Mahabharat mountain ranges are alsoimportant ranges of lesser Himalayas.

•All great valleys like Kashmir Valley, Kangra Valley, Kullu Valleyare present here.

•This region is also known as for its hill stations (for e.g. Kullu-Manali, Kufri, Shimla, Mussoorie, Nainital, etc.).

•The outermost range of the Himalayas is known as Shiwalik,also known as Manak Parbat in ancient times.

•The altitude varies between 900 and 1100 meters in thisrange.

•The width varies between 10 to 50 km.

•These ranges are composed of unconsolidated sedimentsbrought down by the rivers.

•The longitudinal valleys lying between the Himachal andShiwalik are called 'Dun'.

•Unlike typical river valleys, duns have a structural origin andare covered with boulders and gravel originating from theerosion of the Himalayas and the Shiwalik uplands. Major dunsfound in the region are Dehra, Kothri, Chaukham, Patli andKota.

The Himalaya Mountain

•Himalayas have also been divided on the basis ofregions from west to east. The division has been doneon the basis of the rivers flowing in the Himalayanregions. Following is the division: -

1. Punjab Himalayas: This part lies between theIndus and Sutlej. They are also known as KashmirHimalaya and Himachal Himalaya.

2. Kumaon Himalayas: This part lies between Sutlejand Kali river.

3. Nepal Himalayas: This part lies between the Kaliand Tista river.

4. Assam Himalayas: This part lies between the Tistaand Dihang river.

The Brahmaputra marks the eastern border of theHimalayas.

Beyond the Dihang gorge, the Himalayas bend sharplytowards south and form the Eastern hills or Purvachal.

These hills run through the north eastern states of India.

They are mostly composed of sandstones (i.e. Sedimentaryrocks).

These hills are covered with dense forest.

These hills are composed of the Patkai Hills, Naga Hills,Manipuri Hills and Mizo Hills.

The northern plain of India is formed by three river systems, i.e.the Indus, the Ganga and the Brahmaputra; along with theirtributaries.

This plain is composed of alluvial soil which has been depositedover millions of years.

The total area of the northern plain is about 7 lakh square km.

It is about 2400 km long and width is about 240 to 320 km .

Northern plains are most densely populated areas of the country.

Here, we find alluvial soil, thus making the plain very fertile andagriculturally very productive.

Because of the three river systems, i.e. the Indus, the Ganga andthe Brahmaputra; along with their tributaries, availability of wateris there in abundance through the year.

Punjab Plains:

The Punjab plains form the western part of the northernplain.

This is formed by the Indus and its tributaries; like Jhelum,Chenab, Ravi, Beas and Sutlej.

A major portion of this plains is in Pakistan.Doabs arefound in Punjab plains.

Doab (do, "two" + ab, "water" or "river"). It is a region orland lying between and reaching to the meeting of the tworivers.

Ganga Plains:•This plain extends between Ghaggar and Tista rivers.•The northern states, Haryana, Delhi, UP, Bihar, part of Jharkhand and West Bengal in the east lie in the Ganga plains.

Brahmaputra Plains:•This plain forms the eastern part of the northern plain and lies in Assam.

The Peninsular plateau is a tableland which contains igneousand metamorphic rocks.

It is composed of the oldest rocks because it was formed fromthe drifted part of the Gondwana land.

Broad and shallow valleys and rounded hills are thecharacteristic features of this plateau.

The plateau can be broadly divided into two regions, i.e. theCentral Highlands and the Deccan Plateau.

One of the important features of the peninsular plateau is theblack soil area which is known as the Deccan Trap.

This black soil originated from the volcanic eruption which isvery fertile for cotton cultivation.

The Central Highlands lies to the north of the Narmada river.

It covers the major portion of the Malwa plateau.

Situated between Narmada river in the north and Vindhyan ranges inthe south.

Aravalis is situated in the North West.

It covers Malwa plateau, Bundelkhand , Baghelkhand andChotanagpur plateau.

The rivers in this region flow from southwest to northeast (i.e.Chambal, Sind, Betwa, Ken, Son, etc.); which indicates the slope of thisregion.

It is wider in the west and narrower in the east.

Bundelkhand and Baghelkhand mark the eastward extension of thisplateau.

The plateau further extends eastwards into the Chotanagpur plateau.

The Peninsular Plateau

The Deccan Plateau lies to the south of the Narmadariver and it is triangular in shape.

The slope of the Deccan Plateau is from west to east.

Most of the rivers flow from west to east.

The Satpura range makes its northern part.

The Mahadev, Kaimur Hills and Maikal range make itseastern part.

It extends into the north east which encompassesMeghalaya, Karbi-Anglong Plateau and North CacharHills.

Garo, Khasi and Jaintia hills are the prominent ranges;starting from west to east.

Western Ghats stretch from the Tapi River to Kanyakumari. ButThe Eastern Ghats stretch from Mahanadi Valley to the Nilgirisin the south.Western Ghat's average width is 50 to 80 km. But EasternGhat's width varying from 100 to 200 km.Western Ghats is source of many large rivers but no big riveroriginates from the Eastern Ghats.Western Ghats are continuous and can be crossed throughpasses only. But Eastern Ghats has been divided into severalparts by large rivers.Western Ghats average elevation is 900 to 1,600 meters Butthe average elevation of Eastern Ghats is about 600 metresabove sea level.Highest Peak of Western Ghats: Anai Mudi (2695 meters).Highest Peak of Eastern Ghats: Mahendragiri (1501 meters).

The Indian desert is also known as the Thar Desert.

The Indian desert lies towards the western margins ofthe Aravali Hills.

This region gets very less rainfall which is less than 150mm in a year.

The climate is dry and vegetation is very less.

Luni is the only large river but some streams appearduring rainy season. It is a river of western Rajasthanwhich originates in the Pushkar valley of the AravalliRange, near Ajmer and ends in the marshy lands of Ranof Kutch in Gujarat.

Crescent-shaped dunes (barchans) are found in thisarea.

The Western Coastal Plains is a thin strip of coastal plain with a widthof 50 km between the Arabian Sea and the Western Ghats.

It is divided into three sections. The Konkan; (Mumbai – Goa) in thenorth. The Kannada Plain makes the central part and the Malabar coaststretches in the south.

The Eastern Coastal Plains is a strip of coastal plain with a width of 100- 130 km between the Bay of Bengal and the Eastern Ghats

It is divided into two parts. The northern part is called Northern Circar.The southern part is called the Coromandel Coast.

Extensive deltas are formed by large rivers like Mahanadi, Godavari,Krishna and Kaveri.

Chilka lake is the largest salt water lake in India situated on the easterncoast.

The Coatal Plains of India

India has two group of islands (i.e. Lakshadweep in the ArabianSea and Andaman & Nicobar Islands in the Bay of Bengal).

The Lakshadweep Islands are coral islands and covers anarea of 32 sq km. Its administrative headquarter isKavaratti .

Andaman & Nicobar are a group of 324 islands which arevolcanic in nature.

This group of islands can be divided into two groups. TheAndaman is in the north and the Nicobar is in the south.

These islands are located close to equator and thus,experience equatorial type of climate and also have thickforest cover.

Both group of islands have rich biodiversity (flora &fauna).

Lakshadweep Island

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